There are many instances wherein it is necessary to treat a variety of liquids to remove deleterious or undesirable matter therefrom. One such instance relates to the treatment of water. In many parts of the world, there exists a need for potable water. In many locations, there are a variety of sources available for providing water but the water from such sources contains deleterious or undesirable matter therein. One such matter relates to nitrates, such as NO.sup.3. While several types of apparatus and methods have been used to remove such nitrates at least to the extent to make the water potable, there still remains a need for an efficient and economical system for the removal of such nitrates from such water. In one type of apparatus used to try to remove such nitrates, the water is passed through apparatus that is designed to remove such nitrates. The apparatus comprises an outer tube having an inlet and an outlet. Inside of the tube, a plurality of ultra violet lamps are mounted in a circumferentially spaced apart relationship. The ultra violet lamps emit light at a frequency designed to break down the nitrates in the water. The water flows through the inlet and around the ultra violet lamps and out through the outlet. While the apparatus does function to break down at least a majority of the nitrates in the water, a great many of the broken down nitrates rejoin together so that deleterious or undesirable nitrates remain in the water.